Surface Functionalization of Biomaterials by Plasma and Related Technology

The interactions between biomaterials and biological tissues and body fluids depend on the surface properties of the biomaterials and biological interactions and response. However, many types of current biomaterials with favorable bulk characteristics cannot produce the desirable biological and biochemical effects and surface modification is one of the effective ways to alter selectively the surface properties of biomaterials and biomedical implants. By means of plasma surface modification, predesigned surface properties such as biocompatibility and bacterial resistance can be endowed and at the same time, the inherent bulk properties such as mechanical strength can be maintained. Our research group has been conducting research on plasma immersion ion implantation and deposition (PIII&D) for more than 20 years. It is a non-line-of-sight technique and especially suitable for biomaterials and biomedical implants with a complex shape. Moreover, since the interface between biodegradable biomaterials and tissues and body fluids is dynamic, PIII&D offers the unique capability to optimize the interfacial physics and chemistry to achieve controlled and timely degradation and drug release. In this keynote presentation, recent research activities in the Plasma Laboratory of City University of Hong Kong pertaining to surface treatment of biomaterials and biomedical devices, especially biodegradable and antibacterial materials, will be described.